Name: Ian Forsyth
Who is asking: Student
Level: Secondary

Question: Given the points A(0,0) B(60,10) C(24,d) find the equation of the parabola. leave the equation in terms of x, y and d if the general form of a quadratic is y = ax2 + bx + c.

Note: B(60,10) is not a turning point

Hi Ian,

I assume that you want the parabola that passes through A, B and C. If the parabola passes through a point then the coordinates of the point satisfy the equation of the parabola.

Substituting A, B and C into the equation of the parabola gives

0 = a 02 + b 0 + c
10 = a (602) + b 60 + c
d = a (242) + b 24 + c

The first equation implies c = 0 and the second and third equations become

10 = 602 a + 60 b
d = 242 a + 24 b

Solve these equations for a and b.

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